update year in date field

I have an Access database where I am trying to update just the Year of a field that is Date/Time type (DATEFIELD) but keep balance of date (its a Y2K repair).
I have tried :
Update TABLENAME
Set Year(DATEFIELD)=2003
WHERE Year([DATEFIELD])=1903
So if the current value is 12/1/1903 I would like it to be updated to 12/1/2003